This invention relates to a catheter and more particularly to a catheter which is used to improve the success of surgically correcting a nasolacrimal duct obstruction.
It is frequently necessary to correct, by way of surgery, a nasolacrimal duct obstruction. One method of correcting a nasolacrimal duct obstruction is through the silastic intubation of the nasolacrimal duct. In such a procedure, the free ends of a silastic tube are inserted downwardly into, and through, the puncta, canaliculi, nasolacrimal sac and nasolacrimal duct with the lower ends of the silastic tubing being positioned within the nose (inferior meatus) below the lower end of the nasolacrimal duct. The ends of the silastic tubing are normally cut so they do not protrude below the lower end of the patient's nose. The purpose of the silastic tubing is to provide a flow path for the tears to drain downwardly through the system around the exterior surface of the tubing.
One method of fixation of the silastic tubing is through the use of a rubber catheter which embraces the silastic tubing from the nasolacrimal sac to the lower end of the nasolacrimal duct. Knots or sutures are then employed to prevent upward displacement of the silastic tubing with respect to the cuff and to prevent downward displacement of the cuff with respect to the tubing.
Although fixation of the silastic tubing in the nasolacrimal system is a problem, the most troublesome problem is that scar tissue forms around the tubing thereby resulting in an obstruction which prevents tears from passing downwardly through the system around the exterior of the tubing.
In an effort to overcome the above-identified problems, applicant devised a catheter for use in the surgical correction of a nasolacrimal duct obstruction and the same was described in the co-pending application. Although the catheter of the co-pending application did satisfactorily perform in almost all cases, it has been found that the catheter sometimes migrates upwardly into the nasolacrimal sac. It has been found that such upwardly migration can be eliminated and the catheter immobilized by providing an enlarged portion at the lower end of the shank of the catheter.
It is therefore a principal object of the invention to provide a catheter for use with silastic tubing used in correcting nasolacrimal duct obstruction.
A further object of the invention is to provide a catheter of the type described which includes large portions at the upper and lower ends thereof to stabilize or immobilize the catheter.
Yet another object of the invention is to provide a catheter for use in the procedure described including enlarged portions at the upper and lower ends thereof which prevent longitudinal displacement of the catheter and the silastic tubing extending therethrough which can be left in vitro for two to six months without significant discomfort.
Yet another object of the invention is to provide a catheter for use in the described surgical procedure including enlarged portions at the upper and lower ends thereof which may be easily compressed to facilitate the postoperative removal thereof.
These and other objects of the present invention will be apparent to those skilled in the art.